Her Majesty the Queen v. Marc Cyr-Langlois

(Quebec) (Criminal) (By Leave)


Criminal law - Evidence - Criminal law - Evidence - Presumption of accuracy and presumptions of identity in prosecutions for driving with blood alcohol level over legal limit - Failure to observe accused prior to administration of breathalyzer test - Whether recommendations have effect of creating additional burden of proof for Crown, with respect to improper operation of breathalyzer instrument, in order for Crown to benefit from presumptions of identity and accuracy in s. 258 Cr.C. - Whether accused can discharge burden of proving improper operation of breathalyzer instrument on basis of mere theoretical possibility of inaccurate result rather than evidence of direct connection between improper operation and reliability of results.


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Mr. Cyr-Langlois was charged with two counts of impaired driving.

He was stopped while driving his vehicle and taken to the police station for a breathalyzer test. Around 12:58 a.m., he was put in an interrogation room while a police officer was taking the steps required for him to exercise his right to counsel and another police officer was preparing the breathalyzer device. The officer who testified at trial was the one who had prepared and administered the breathalyzer test. He was unable to say that Mr. Cyr-Langlois had been observed during the 15- or 20 minute period preceding the test. The first blood alcohol test was administered at 1:08 a.m. and the second at 1:30 a.m. The results showed a blood alcohol level exceeding 80 mg of alcohol in 100 mL of blood.

At trial, Mr. Cyr-Langlois brought a preliminary motion seeking to rebut the presumption that the results of the blood alcohol tests were valid. The issue was whether the officer who had operated the breathalyzer instrument had completed the necessary observation period before administering the test and whether evidence that the observation period had not been complied with could deprive the Crown of the presumptions established by s. 258(1)(c) of the Criminal Code.